Help to start contributions

Hi, I'm Angel Cajas from Bowpi, we are ready to submit the next features for code review:
*Subrates
*Transaction Detail Table
*Calculation of overdue amount for daily charges
As this useful article I understand that we need to create an issue before creating a pull request
and would like to know which of one of this features are you most interested to be included to start this process .
Best Regards and thanks for your attention,
Angel